# numbers是一个整数数组
# 求数组中不重复的元素有几个？

def how_many(numbers):
    # 请在这里填写你的代码
    pass

# 答案应该是4
numbers_1 = [2,7,11,15]
answer = how_many(numbers_1)
print(answer)

# 答案应该是3
numbers_2 = [3,2,4,2]
answer = how_many(numbers_2)
print(answer)

# 答案应该是1
numbers_3 = [3,3,3,3]
answer = how_many(numbers_3)
print(answer)